SEC Filings

Intangible assets at September 30, 2017 and December 31, 2016 consisted of the following (in millions):

September 30, 2017

December 31, 2016

Gross

Gross

Carrying

Accumulated

Carrying

Accumulated

Amount

Amortization

Net

Amount

Amortization

Net

Amortizable intangible assets:

Customer relationships

$

3,429.8

$

(279.2

)

$

3,150.6

$

3,235.0

$

(154.6

)

$

3,080.4

Capitalized software

152.6

(65.2

)

87.4

136.5

(41.8

)

94.7

Trade names

25.0

(20.8

)

4.2

25.0

(2.1

)

22.9

Agreements, contracts and other

13.8

(6.3

)

7.5

13.2

(4.7

)

8.5

Total amortizable intangible assets

3,621.2

(371.5

)

3,249.7

3,409.7

(203.2

)

3,206.5

Non-amortizable intangible assets:

Trade names

430.0

—

430.0

460.0

—

460.0

Restrictive covenant arrangements

8.0

—

8.0

9.0

—

9.0

Total non-amortizable intangible assets

438.0

—

438.0

469.0

—

469.0

Total intangible assets

$

4,059.2

$

(371.5

)

$

3,687.7

$

3,878.7

$

(203.2

)

$

3,675.5

Amortization of intangible assets for the three months ended September 30, 2017 and 2016 was $57.1 million and $22.3 million, respectively, and $168.7 million and $63.8 million for the nine months ended September 30, 2017 and 2016, respectively. Estimated amortization of intangible assets for the remainder of 2017 and each of the following five years and thereafter is $59.9 million, $202.3 million, $193.1 million, $186.2 million, $181.8 million, $176.5 million and $2.25 billion, respectively. The Company expects to recognize amortization of all intangible assets over a weighted average period of 18.0 years with no expected residual values.

(9) Other Accrued Liabilities

The following table presents a summary of items comprising other accrued liabilities in the accompanying consolidated balance sheets as of September 30, 2017 and December 31, 2016 (in millions):